The objective is to obtain more accurate information relating to the very low birth weight (VLBW) infant, less than 1500 grams, than is now available from the United States vital records. This objective will be accomplished by the following: 1)mailing or administering a questionnaire to mothers of VLBW infants, mothers of fetal deaths, and a sample of mothers of moderately LBW infants (1500-2499 grams) and normal birth weight infants (greater than 2500 grams) in order to obtain and verify information from the prenatal, perinatal, and post-neonatal periods; 2) conducting telephone follow-up interviews on non-respondents and incomplete respondents, and a 10 percent sample of study mothers to obtain and/or verify information on the questionnaires; 3) developing procedures for abstracting information from hospital and physician records, including otherwise unavailable or missing information on morbidity, lifestyle, and socioeconomic indicators of the study subjects; and 4) preparing an edited data tape for NICHD. In addition, mortality and results of follow-up evaluations will be available through the first year of life for this birth cohort.